Cardiac defibrillators are medical devices for treating patients who have experienced an episode of ventricular tachycardia or ventricular fibrillation. Cardiac defibrillators are often implanted within a patient to detect and treat ventricular tachycardia or ventricular fibrillation. Implantable cardioverter-defibrillators (ICDs) include a small battery-powered electrical impulse generator that is implanted in patients who are at risk of developing ventricular fibrillation. The ICDs are programmed to detect cardiac arrhythmia and correct it by delivering a jolt of electricity through electrodes that are introduced into the heart.
ICDs can keep a record of the heart's activity when an abnormal heart rhythm occurs. With this information, an electrophysiologist can study the heart's activity and ask about other symptoms that may have occurred. Sometimes the ICD can be programmed to pace the heart to restore its natural rhythm.